1976-2013: series of pieces for string quartet performed by the Margand Quartet and various formations.
1980-1990: series of records and performances entitled Chromophonie, with the aim of making known the multiple ways of Yochk'o's music, but also of his painting. The third and last part of Chromophonie was born on November 22, 1983 at the Elysée Montmartre, in the form of a total show combining music, dance, painting and light show. Built on the opposition between written parts, close to contemporary music, and improvisations closer to jazz, the suite composed for this world premiere is served by a string quartet (Jacques Parrenin, Jean-Claude Dewaele, John Cohen, René Benedetti), a wind quartet (Michel Godard, tuba; Bruno Rousselet, bassoon; Alain Brunet, trumpet; Philippe Gisselmann, soprano saxophone), a large rhythm section (Siegfried Kessler, piano; Jean-Marie Colin, synthesizer; Jean-François Jenny-Clark, double bass; Peter Gritz, drums; François Causse, percussion), Yochk'o, principal soloist on soprano and tenor saxophones and bass clarinet, Didier Lockwood, finally, as a special guest on electric violin.
1983-2010: "Trabla" series: 'book' of twelve opus, including :
- Trabla n° 1 (Torma) for alto saxophone.
- Trabla n° 2 (Techouba) recorded in 1988 on the album La Voie Scriptorale with Alain Bouhey.
- Trabla n° 3 dedicated and interpreted by the saxophonist André Beun who plays in playback on a magnetic tape.
- Trabla n° 4 for haubois and sound sculptures, dedicated and interpreted by Làslo Hadàdy from the Ensemble Intercontemporain.
- Trabla n° 6 for soprano solo.
- Trabla n° 9 for soprano voice, illustrating three poems by Mallarmé, Baudelaire's Tomb, accompanied by a B-flat clarinet, Edgar Poe's Tomb, with alto clarinet and Anniversary with bass clarinet.
- Trabla No. 10 is due to evolve. Initially written for baritone saxophone and performed by the talented Laurent Matheron, it is embellished in 2009 with parts of malabar, tromboz and zirnus, three sound sculptures. Another version, another "landscape", exists for piano and soprano.
-Trabla No. 12 was presented in 2008 in New York as part of a Hungarian programme (Bartòk, Eötvös, Kurtag and... Seffer) before being expanded with an additional part of thirteen saxophones.
"These virtuoso pieces for solo wind instruments, like L. Berio's Sequenze or C. Ballif's Solfegiettos, contain all the characteristics of Yochk'o's music: Central European roots, lyricism, serialism, improvisation, rhythmic momentum... The main difficulty, but also all the peculiarity of these trablas lies in the part of freedom left to the interpreter. If the music is very precisely written, the environment, the tempi, the cutting, the improvisations... remain to be experimented and fixed for each interpreter. This possibility left to the musician forces him to wonder about the meaning of this music, and, contrary to more open pieces, it is necessary to overcome the difficulties of the text. The series of Trablas seems to me of paramount importance in Sefferian production and in music for solo instrument, comparable to Berio's Sequenze". (Laurent Matheron, 2010).
1995: Recording of an Oratorio with the choirs of the Tomkins Vocal Ensemble, conducted by Janos Dobra.
2007: Métamorphoses Dansées for a Partita by Bach, choreography by the Ballet Scriptoral and a video animation by Alain Bouhey, based on 118 tableaux by Yochk'o.
2008: The Ten Seven Seasons, rereading / transformation of Vivaldi's Four Seasons with an animated film by Alain Bouhey.
2010: Sonata for cello (Gordonka-Sonata).
2018: Nokram Delirium Robotik for narrator, tarogatos quartet and percussion.